The invention relates to a cross member for a universal joint. The cross member includes a base member arranged at the center of the cross member. Four arms project from the base member and extend away from the center. Opposing arm pairs define a common axis. The axes intersecting one another in the center of the universal joint at a right angle. Each arm includes a cylindrical running face to receive rolling contact members of a rolling contact bearing. Each running face is arranged concentrically around its respective axis. The base member, in the region of transition to an arm, includes an annular and radially extending shoulder. The shoulder is arranged co-axially around the respective axis.
DE-OS 27 21 706 describes a cross member for a universal joint. Here, the arms each change step-like into the annular shoulder of the base member. Universal joints of this type are primarily used in driveshafts. Two universal joints are connected in a rotationally fast way by telescopically connected shaft portions. At its input end and at its output end, the universal joint includes a joint yoke. The joint yokes are connected to one another in a rotationally fast way by the cross member. The arms of the cross member are supported in rolling contact bearing bushes which are accommodated in bores in the joint yokes. The torque transmitting ability of a universal joint is largely determined by the design of the joint yokes, the cross member and the bearings. In particular, the torque transmitting ability is limited by the strength of the highly loaded transition regions between the arm running faces and the base member. This may result in disadvantages and problems, especially in heavy-duty joints used in rolling mill drives.